The invention relates to wastewater treatment systems and in particular to wastewater treatment systems in which conversion of organic wastes and light energy to glucose takes place. Specifically, the invention relates to a complex system in which wastewater and other associated discharges are treated anaerobically and aerobically in a tank complex system where waste organics are reduced to inorganic forms available for algal culture in the uniquely designed rapid growth tanks.
This invention is an improved component of a pending application of the present inventor for a Controlled Natural Purification System for Advanced Wastewater Treatment and Protein Conversion and Recovery, Ser. No. 095,969, filed Nov. 20, 1979, now U.S. Pat. No. 4,267,038.
In the prior art, and in particular in the aforementioned pending application for a controlled natural purification system, the culture liquid in the last stage is controlled by a rigid vertically-moving circular weir.
The vertically-moving circular weir of the prior art is, by general description, a rigid cylindrical structure which is open at each end of the cylinder. The circular weir, when in position for operation, stands upright on one end. The circular-weir interfaces with the surrounding structure through gaskets.
The vertical movement of the vertically-moving rigid circular weir is provided by a cable suspension system attached to the rigid circular weir at specific points around the upper periphery of the weir. Electric motors lift the weir and lower the weir by means of reels for the cable suspension system.
The vertical movement of the rigid circular weir controls the depth of the culture liquid in the algae growth reactor. By lowering the weir the algae-free liquid is decanted over the top of the rigid circular weir. By moving the rigid circular weir slowly, settling algae is retained in the algae growth reactor, during algae separation (including harvesting) procedure. When the rigid circular weir is raised, the algae growth reactor may be filled again with more culture liquid for the growing of more algae.
The present invention is an improvement over the heavy vertically-moving rigid circular weir, which is also subject to some leakage at the gaskets mentioned previously. The present invention provides a toroidal shaped inflatable type of weir that has a more or less permanent interface connection which is water-tight. The inflation and deflation of the inflatable weir controls the culture liquid in the algae growth reactor as will be described hereinafter.
The present invention provides a pneumatic toroidal weir. The toroidal weir being more or less doughnut shaped as will be described hereinafter.
It is, therefore, an object of the invention to provide a toroidal shaped weir for controlling the culture liquid in an algae growth reactor, and for separating the algae from the effluent and increasing the concentration of the algae.
It is another object of the invention to provide a toroidal shaped weir that is inflatable.
It is also an object of the invention to provide a toroidal shaped weir that has a more or less permanent type connection to the algae growth reactor to prevent leakage.
It is still another object of the invention to provide a toroidal shaped weir that does not require a cable system to operate it.
Further objects and advantages of the invention will become more apparent in the light of the following description of the preferred embodiments.